dougherty



March 21, 1933. R. J." DOUGHERTY ELECTRICAL CONTROLLING SYSTEM FOR GASWATER HEATERS Filed Nov. 14, '1951 2 Sheets-Sheet 1 L FFIII WHY/V703floase'r t/. Dauamser);

R. J. DOUGHERTY Filed Nov. 14, 1931 ELECTRICAL CONTROLLING SYSTEM FORGAS WATER HEATERS March 21, 1933.

l atentecl Mar. 21, 1933 UNITED STATES ROBERT J". DOUGHERTY, OF AMBLER,

PATENT OFFICE A PENNSYLVANIA, ASSIGNOR TO JOHN WOOD MANU- FAOTURINGCOMPANY, OF CONS HOI-IOGKEN, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIAELECTRICAL CONTROLLING SYSTEM FOR GAS WATER HEATERS Application filedNovember 14, 1931. Serial No. 575,042.

perature of the atmosphere surrounding the thermostat. That is to say,when said atmosphere reaches a predetermined temperature, the supply ofgas to the burner is diminished to such a degree that only a small pilotflame is maintained, but such flame is enlarged by automatically openingthe gas valve, by electrically controlled means, when the temperature atthe thermostat falls below a predetermined degree. Such thermostaticcontrolling means is also operative upon the motor which actuates thewater circulating pump. Moreover, said pilot flame is in cooperativerelation with a thermostatically controlled switch; so that if and whensaid flame is accidentally extinguished, the flow of gas through thepilot burner is automatically stopped, to not only prevent waste of gasthereat but eliminate the possibility of ultimate explosion of gasflowing from the burner unignited.

Such apparatus conveniently includes heater sections of a cellular type,formed of congeries of thin copper flue tubes having their opposite endsenlarged and connected, laterally, by solder, to form water spacesaround the tubes. eflicient in the transfer of heat from the flue gasesto the water, but it is necessary to avoid raising the temperature ofsuch cellular structure to such a degree that the water pressure woulddisrupt the soldered joints. Therefore, such apparatus includes meansauto matically insuring that the water shall be actively circulating inthe heater sections, each time the heating effect of the burnerisaugmented in response to the operation of said thermostat to producemore heat, to thus Such heater units are extremely prevent overheatingthe soldered joints by the increased consumption of gas. Such meansincludes anelectrically operated and controlled water pump, whereby thewater is forcibly circulated in the heater system at such a rate as toabsorb substantially all of the heat from the products of combustion.Although that effect is desirable for efliciency of combustion of thefuel, it leaves'the prodnets of combustion at such low temperature thatthe mere convection force thereof is sometimes insuflicient to alonedischarge the products of combustion through a flue to a chimney orother discharge outlet. Therefore, said apparatus preferably includes anelectricallyoperative and controlled fan in said flue, for supplementingthe convection force of the products of combustion to effectivelydischarge them from the heater. 7

Ordinarily, such apparatus is electrically controlled by a complicatedsystem wherein both high and low voltages are employed in cooperativerelation; for instance, a portion of the circuitmay be energized at 110volts and another portion at 20 volts.- Such a construction andarrangement not only necessitates the employment of a transformer togenerate the low voltage energy from the high voltage energy, but ismore difficult and, consequently, costly to wire and requires a personhighly skilled in the art to not only initially connect it but to makeany subsequent repairs and avoid destruction of parts of the apparatusincluded in the low voltage circuit by accidental connection with thehigh voltage circuit. Therefore, an object and effect of my presentinvention is to provide for such a heater as above described a muchsimpler electrical controlling systemv which may be energized entirelyfrom an ordinary 110 volt'house lighting circuit; eliminating thedelicate and costly controlling elements which have heretofore beenrequired to be energized by the low voltage circuit. 7

My invention includes the various novel features of construction andarrangement hereinaftermore definitely specified.

' In said drawings; Fig. I is a vertical sectional view of such a heatercasing taken on the line I, I, in Fig. II, showing the other elements ofthe heater in elevation, as seen from the front.

Fig. II is a vertical sectional view of the heater casing taken on theline II, II, in Fig. I and showing some of the interior elements of theheater in elevation, as seen from the right hand side of Fig. I.

Fig. III is a wiring diagram showing the connection and cooperativerelation of the various elements of the heater with a preferredembodiment of my improved electrical controlling system.

In said figures; the outer casing 1 of the heater, which is convenientlyformed of sheet metal, is rectangular in plan with its walls connectedby corner angle bars 2. The cylindrical heat insulating jacket 3 ismounted with its axis vertical in one corner of said outer casing 1surrounding the cylindrical tubular water jacket 4 inclosing thecombustion chamber 5. Water is supplied to said heater through the pipe7 and rotary pump 8, and conduit 9 leading to said jacket 4. -As shownin Fig. II, said pump 8 is directly connected with the armature shaft 10of the electric motor 11.

As shown in Fig. II, said water jacket 4: is connected by the conduit 13with the heater unit section 14: which is connected by the coupling 15with the similar heater unit section 17 from which the hot waterdischarge conduit 18 leads to suitable radiators.

The main gas burner 20 is mounted in said combustion chamber 5 andsupplied with gas from the pipe 21 through the conduit 22 under controlof the valve 23 in the casing 24: arranged to be opened by the electricmotor 25 and closed by the spring 26. The device indicated at 27 in Fig.I is a regulator of the diaphragm type which renders the pressure of thegas supplied to said burner 20 substantially uniform, regardless offluctuations in pressure of the gas supplied to the heater.

I find it preferable to retard the flow of products of combustionthrough the heater by directing them through the battle ring 28 againstthe baflie plate 29. Said products pass around said baiiie plate 29, andthrough congeries of small open copper tubes extending vertically insaid heater sections 14 and 17. Said tubes have hexagonal enlargementsat their opposite ends, which are soldered to-- gether. The watercirculates around said tubes through the interstices between them andabsorbs the heat from the products of combustion which pass through saidtubes into the horizontally extending flue casing 30, which has the flueoutlet flange 31 engaging the flue pipe 32. 7

V I find it convenient to create a forced draft of the products ofcombustion from said chamber 5, through said flue flange 31, by means ofthe rotary fan 34 which is mounted on the armature shaft 35 of theelectric motor 36. Said flue casing 30 is spaced from the jacket 3 bythe insulating jacket 38 surrounding said heater sections 14 and 17, andis rigidly connected with said jacket 4, conveniently by the bolts 39and nuts 40 shown in Fig. I; said nuts being accessible through the handhole 41 in said casing 30 which is normally closed by the cover d2.

The pilot burner 45 is supplied with gas through the conduit 46, fromthe pressure side of the valve 23 so that, under normal circumstances, aflame a7 is maintained at said pilot burner in position to ignite thegas issuing fromsaid burner to maintain the main flames 4E8. However, toinsure that gas shall not be supplied to said main flames through saidvalve 23 when the water circulating pump 8 is not operating, and thatsaid valve 23 shall be shut to terminate the operation of said burner 20if and when the temperature of the water in the system exceeds apredetermined degree, and to insure that said valve shall be shut if andwhen the pilot flame 47 is accidentally extinguished, and that all ofthe elements of the apparatus arejmaintained in propercooperativerelation when they are operated; I provide an electriccontrolling system cooperatively connecting them and preferably such asshown in Fig. III.

I As shown in Fig. III, the heater controlling circuit comprising theconductors 50 and 51 may be energized from any suitable source,preferably the 110 volt supply circuit comprising the conductors 52 and53. Said circuit connects said pump motor 11, valve motor 25, and fanmotor 36 in mul tiple relation between said conductors 50 and 51, asshown in Fig. III. The adjustable room thermostat 5a may be of anyconvenient form and includes a switch 55in said conductor 50. Theconstruction and are rangement thereof are such that said the-rmostat 54operates to close said heater cir cuit, by said switch 55, whenever thetemerature of the atmosphere surrounding it falls below the degree forwhich it is set, and to open said circuit when said temperature risesabove that predetermined degree.

In order to break said heater circuit, regardless of the position of theswitch 55, if and when the flame 47 is extinguished, I provide the bulb57 in position to be heated by said flame 7 and connected by the tube 58with the corrugated metal bellows 59 which carriesthe safety pilotswitch member 60 which normally closes said circuit between theterminals 61 and 62 in said conductor 5O whenever the fluid contents ofsaid bulb 57 and tube 58 are heated to a predetermined degree However,the arrangement is such that if said flame 47 is extinguished, the fluidin said bulb 57 tube 58, and bellows 59 contracts, and breaks saidcircuit by movement,

by said pilot flame d7.-

of said switch member 60 to the left away from said terminals 61 and 62.

All three motors 11, 25, and 36 are thus controlled, together, both bythe room switch 55 and by the safety pilot switch 60. However, it isdesirable to continue the circulation of water in the system by the pump8 and to continue to eliminate products of combustion from the chamber 5by the fan 34 when the main gas valve 23 is closed, if such closure iselfected because the water in the system has become too hot. Therefore,I arrange the pump motor 11 and fan motor 36 in series relation withboth of said switches 55 and 60, although saidmotors are in multi plerelation with each other, as shown in Fig. III, but provide anotherswitch 64 to open and close the circuit of said valve motor 25,independently of said motors 11 and 36, in accordance with thetemperature of the water in the heater, say at the delivery pipe 18.Said switch 64 is normally closed by the spring 65 but is adapted to beopened against the stress of said spring 65 conveniently by means of thecorrugated metal bellows 67 containing a heat expansive fluid and incooperative relation with said water pipe 18, as indicated in Fig. III.It is to be understood that the stress of said spring 65 upon saidswitch 64; tending to close it, may be varied by adjustment of the screw68 to thus vary the temperature at which said switch is opened, againstthe stress of said spring 65, by said expansible device 67.

As indicated in Fig. III, said valve 23 may have its stem 69 providedwith the gear rack 70 engaging the gear pinion 71 on the armature shaft72 of said valve motor 25 so that wheneversaid heater circuit is closedthrough said motor 25, the latter turns, counterclockwise in Fig. III,to open said valve 23, against the stress of said spring 26. Wheneversaid heater circuit is broken through said valve motor 25, at either ofsaid'switches 55, 60, or 64, the spring 26 is effective to close saidvalve 23 and thus permit the heater to be gradually cooled by thecontinued operation of the water pump motor 11 and flue fan motor 36.Moreover, the gas valve motor 25 cannot be operated to open said gasvalve 23 to the main burner 20 when the pump motor 11 and fan motor 36are deenergized by the opening of the circuit at either of the switches55 or 60. Therefore, the maximum efliciency and safety of the device aresecured.

However, it is to be imderstood that any suitable form ofthermostatically controlled gas valve and switches may be employed inlieu of those which I have chosen for illus-' tration. Therefore, I donot desire to limit myself to the precise details of construction orarrangement or method of operation herein set forth, as it is obviousthat various modifications may be made therein, without departing fromthe essential features of my invention,

I claim: v 1. In an electrical controlling system for a gas waterheater, the combination with a accordance with atmospheric temperature;and means for supplying the entire circuit current at the same voltage;whereby with said multiple circuit is closed and" said valve motor andpump motor energized when said room switch .is closed, and'deenergizedwhen that switch is opened; and said branch circuit through said valvemotor is broken, independently of the branch circuit through said pumpmotor, and the gas valve closed, if and when. the'temperature of thewater heated exceeds a predetermined degree.

2. In an electrical controlling system foragas water heater, thecombination with a main gas'burner; of a pilot gas burner-in cooperativerelation with said main gas burner; an electrically operative andcontrolled main gas burner valve; an electrically operative andcontrolled water pump for circulating water through said heater; anelectric circuit including the pump'motor and main gas valve motor, inmultiple relation; a thermostatically operative electric switchcontrolling the branch circuit through said main gas valve motorindependently of said other motor, for opening and closing that branchcircuit in accordance with the tem- V perature of the water in saidheater; a thermostatically operative electric room switch for openingand closing the multiple circuit through said motors contemporaneouslyin accordancewith atmospheric temperature; a thermostatically operativeelectric pilot switch, in series with said room switch,'for opening andclosing said multiple circuit through said motors contemporaneously, inaccordance with the temperature at said pilot burner; and means forsupplying the entire circuit with current at the same voltage; wherebysaid multiple circuit is closedand said valve motor and pump motor areenergized when said room switch is closed, and

deenergized when that switch is opened; and

if and when the flame at said pilot burner is extinguished, saidmultiple circuit is broken at said pilot switch, whether said roomswitch is closed or not; and said branch circuit.

as defined in the appended claims.

through said valve motor is broken, independently of the branch circuitthrough said pump motor, and the gas valve closed, if and when thetemperature of the Water heated exceeds a predetermined degree.

3. In an electrical controlling system for a gas water heater, thecombination with a main gas burner; of a pilot gas'burner in co=operative relation-with said main gas burner;

an electrically operative and controlled main gas burner valve; anelectrically operative and controlled pump for circulating water throughsaid heater; an electrically operative and controlled fan fordischarging products of combustion from said heater; an electric circuitincluding the pump motor, fan motor,

and main gas valve'motor, in multiple relation; a thermostaticallyoperative electric switch controlling the branch circuit through saidmain gas valve motor independently of said other motors, for opening andclosing that branch circuit in accordance with the temperature of thewater in said heater; a thermostatically operative electric room switchfor opening and closing the multiple circuit through all of said motorscontemporaneously in' accordance with atmospheric temperature; athermostatically operative electric pilot switch, in series with saidroom switch, for opening and closing said multiple circuit through allof saidmotors contemporaneously, in accordancewith the temperature atsaid pilot burner; and means for supplying the entire circuit withcurrent at the same voltage; whereby said multiple cir-' cuit is closedand said valve motor, pump motor, and fan motor are energized when saidroom switch is closed, and deenergized when that switch is opened; andif and when the flame at said pilot burner is extinguished, saidmultiple circuit is broken by said pilot switch, whether said roomswitch is closed or not; and said branch circuit through said valvemotor is broken, independently of the branch circuits through said pumpmotor and fan motor, and the gas valve closed, if and when thetemperature of the water heated exceeds a predetermined degree, but'said pump and fan then continue to'operate to reduce the temperature inthe heater to a predetermined degree; 7 i a In testimony 'whereo'f, Ihave hereunto signed my name at Conshohocken, Pennsy vania, this secondday of November, 1931.

ROBERT J DOUGHERTY."

